Drilling fastener



FIG. 1 is a perspective view thereof;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevation thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left-side elevation thereof;

FIG. 6 is a cross section taken along the line A—A in FIG. 3;

FIG. 7 is a cross section taken along the line B—B in FIG. 2;

FIG. 8 is a supplementary view of the fastener at the first step in use;

FIG. 9 is another supplementary view of the fastener at the second step in use; and,

FIG. 10 is a further supplementary view of the fastener at the third step in use.

A rear elevation appearing symmetrical with the front elevation, as well as a right-side elevation appearing symmetrical with the left-side elevation, are excluded from the drawings.

The broken line showing of the drilling surface, drill and hammer is included for the purpose of illustrating environmental structure and forms no part of the claimed design. 

The ornamental design for a drilling fastener, as shown and described. 